import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;

@WebServlet("/blogDelete")
public class BlogDeleteServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //1.检查当前用户是否登录
        HttpSession session= req.getSession(false);
        if(session==null){
            resp.setContentType("text/html;charset=utf8");
            resp.getWriter().write("当前尚未登录，不能删除");
            return;
        }
        User user=(User) session.getAttribute("user");
        if(user == null) {
            resp.setContentType("text/html;charset=utf8");
            resp.getWriter().write("当前尚未登录，不能删除");
            return;
        }

        //2.获取到参数中的blogId
        String blogId=req.getParameter("blogId");
        if(blogId == null || "".equals(blogId)) {
            resp.setContentType("text/html;charset=utf8");
            resp.getWriter().write("当前blogId参数不对");
            return;
        }
        //3，获取要删除的博客信息
        BlogDao blogDao = new BlogDao();
        Blog blog=blogDao.selectOne(Integer.parseInt(blogId));
        if(blog==null) {
            resp.setContentType("text/html;charset=utf8");
            resp.getWriter().write("当前要删除的博客不存在");
            return;
        }
        //4.校验当前用户是否就是作者
        if(user.getUserId() != blog.getUserId()) {
            resp.setContentType("text/html;charset=utf8");
            resp.getWriter().write("当前登录的用户不是作者，没有权限删除");
            return;
        }
        //5.确认无误，开始删除
        blogDao.delete(Integer.parseInt(blogId));

        //6.重定向到博客列表页
        resp.sendRedirect("blog_list.html");
    }
}
